欢迎来到天天文库
浏览记录
ID:39402610
大小:709.50 KB
页数:68页
时间:2019-07-02
《基于空时频编码的MB-OFDM超宽带系统研究》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、北京交通大学硕士学位论文基于空时频编码的MB-OFDM超宽带系统研究姓名:王宇申请学位级别:硕士专业:通信与信息系统指导教师:朱刚20090601=jb塞交道厶堂亟±堂僮i金塞△垦墨!B△g!ABSTRACTABSTRACT:RecentlMUWB(Ultra-WideBand)communicationsattractsintensiveattention,becauseitisapotentialcandidateforshort—rangecommunicationswithveryhig
2、hdatarate.verylowpowerconsumptionandemission.AUWBcommunicationisMB—OFDM(Multi—BandOrthogonalFrequencyDivisionMultiplexing)UWB,beingtakenoutrecentlyyears.Inthischapter,wediscussthecombinationbetweentheMB-OFDMUWB,MIMO(Multiple—InputandMultiple-Output),
3、andSTCs,whichCanimprovetheperformanceoftheconventionalmultimediacommunicationsbetweenportabledeviceswithveryhighdatarates,improvedcommunicationsquality,andlowcost.InaMIMO-OFDMsystem,thesignalistransmittedwithsubcarriersindifferentfrequent,SOthereisaf
4、requentdiversityitself.SotheSTCsimplementinginMIMO-OFDMsystemisnamedSTFCs(Space—Time-FrequencyCodes).AMB-OFDMUWBsystemusingSTFCsiscalledSTFCMB—OFDMUWBsystem.TllispaperusesthegreatsimilaritybetweentheSTFCMB-OFDMUWBsystemsandCOSTBC(ComplexOrthogonalSpa
5、ce—TimeBlockCode)MIMOsystemstoquantifythePEP(pairwiseerrorprobability)oftheproposedsystemandderivethegeneraldecodingmethodfortheimplementedSTFCs.Themaximumachievablediversityorderisfoundtobetheproductofthenumberoftransmitantennas,thenumberofreceivean
6、tennas,andtheFFTsize.ThePaperalsodesignsamethodofdiversityaccordingtothestandardofMB-OFDMUWBsystem.Thismethodcanincreasethediversitygain,andthenimprovethePEPperformance.Inthelastchapter,weconsidertheCO—channelinterferenceofdifferentdevice,fortheSTFCM
7、B—OFDMUWBsystemusedinshort—rangeCOmmunications.Sowederivethebeamforming,whichcanbeusedtorelievetheCClwithangulardiversity.KEYWORDS:MB—OFDM;UWB;STFC;diversitygain;codinggain;beamforming;CI。ASSNO:TN915。142图目录图2.1MIMO系统原理框图………………………………………………………,6图2.2串并变
8、换……………………………………………………………………8图2.3OFDM系统基本模型……………………………………………………..9图2.4多径情况下空闲保护间隔在子载波间造成的干扰…………………….11图2.5加入循环前缀的OFDM符号……………………………………………ll图2-6采用空时编码的发送分集………………………………………………12图2.7两天线空时编码接收机…………………………………………………13图3.1MB.OFDMUWB系统发射端框图……………………………………..15图3.2
此文档下载收益归作者所有